1. Field of the Invention
The present invention relates to the field of object handling employing feedback and in particular to systems for controlling object discharge such as depositing a harvested crop within a container.
2. Prior Art
The present invention while having general application is particularly beneficial when utilized in the harvesting of crops. It takes on added significance when utilized in connection with the harvesting of such crops as tomatoes, potatoes and similar crops. These crops are generally planted in a field in long parallel straight lines separated from one another by a distance sufficient to permit a harvest vehicle to travel between the rows of the plants. In a typical procedure used to harvest crops planted in such a manner, two vehicles are used to perform the harvesting operation. The first vehicle may be designated the harvest vehicle and the second vehicle may be referred to as the collection vehicle. The harvest vehicle typically has a device provided thereon for detaching the entire plant from the roots of the plant and ingesting the plant into the processing area of the harvest vehicle where the plant is shaken or otherwise agitated to an extent sufficient to separate the tomatoes or other crop from the plant. The plant is then shredded and ejected from the rear of the vehicle. The detached crop may then be sorted to separate the ripe crop (e.g., red tomatoes) from the unripe crop (e.g., green tomatoes). In the case of tomatoes such sorting is typically accomplished by a color sorter which automatically separates the red tomatoes from the green tomatoes. The green tomatoes and the otherwise rejected portion of the crop are then ejected from the harvest vehicle. The retained portion of the crop may then be passed through further screening processes which in some instances may be performed by workers that further separate the more desirable part of the crop from the undesirable. Once this final selection is made the desirable portion of the crop is carried by a conveyer system that is mounted on the harvest vehicle. The conveyer system extends upward and outward from the harvest vehicle to the collection vehicle and down into the container located on the bed of the collection vehicle. The collection vehicle also travels across the field between parallel rows of plants and may be traveling in the space between the rows which is adjacent the space in which the harvest vehicle is traveling.
Each of these two vehicles is operated by a driver. It is the general objective of both drivers to so operate their vehicles that the crop which is being carried by the conveyer from the harvest vehicle to the collection vehicle is deposited within the collection vehicle in a way that the crop is not damaged. This generally means that the crop should not fall more than a certain distance, preferably 8 to 10 inches, if bruising is to be avoided.
It is desirable that the drivers of the two vehicles control the vehicles and the conveyer such that the conveyer arm which is mounted on the harvest vehicle and which extends into the container on the collection vehicle does not impact any of the walls of the container and does not contact the floor of the container. The drivers must control the position of the end of the conveyer or any attachments thereto which extend within the container of the collection vehicle so that it does not damage the harvest already deposited in the collection vehicle and such that the crop does not fall more than a certain distance which would damage the crop.
Although the objective of the drivers is relatively easy to express, there are various practical difficulties which arise making it most difficult for the drivers to work together to efficiently accomplish their objective. One of the difficulties results from the fact that each vehicle is independently operated by a separate driver. Each driver in turn is occupied with many considerations which are uniquely determined by the particular vehicle which he is operating. For example the driver which is operating the harvest vehicle must operate his vehicle to enable the mechanism to remove the plant from the ground without cutting too high on the plant and without cutting too low. In the event that the cut is made too high, useful portions of the crop may be lost. In the event the cut is made too low excessive dirt may contaminate the selected crop and sorting is made more difficult. This driver must also be concerned with guiding his vehicle in a straight line, and he must also take care to avoid holes in this path. He is further charged with the supervision of workers stationed on the vehicle to do sorting. This driver must also be concerned with the speed of his vehicle and the speed relative to the speed of the collection vehicle. Since the conveyer mechanism is mounted on the harvest vehicle this first driver also has responsibility for adjusting the elevational position of the conveyer such that it does not come in contact with the crop which has been deposited within the collection vehicle. If the conveyer mechanism is allowed to contact the crop already deposited in the collection vehicle, excessive damage may occur to the crop resulting in a low yield.
Similar considerations and activities occupy the driver of the collection vehicle. This driver must also be concerned with guiding his vehicle in a straight path between the rows of plants, avoiding holes in his path, controlling the speed of his vehicle so as not to cause the conveyer to crash into one end or the other of the container on his vehicle and monitoring the level of the crop deposited in his vehicle.
If the drivers can cooperate to meet their objectives, the collection vehicle will be filled with the crop and a minimal amount of crop will be damaged. The problem of controlling the position of the end of the conveyer within the container on the collection vehicle is not only a result of the many considerations which occupy the mind of the drivers, but is also compounded by the physical dimensions of the container. This problem can be illustrated by considering that if the conveyer is positioned near the middle of the length of the container there is a great margin for error and ample time within which to raise the conveyer out of the container. However, as the conveyer approaches one end or the other of the container it becomes clear that less and less time is available within which to raise the conveyer out of the container in the event that one of the two vehicles suddenly changes velocity. This translates to a much smaller margin for error. It is therefore desirable that as the conveyer approaches one end or the other of the container the conveyer should be kept at a greater elevation above the floor of the container so that less time is required to raise the end of the conveyer above the walls of the container.
If the operators of these two vehicles are successful in meeting their objectives, the container will be filled with a crop which is relatively undamaged, and the integrity of the conveyer will be maintained. If the drivers are not successful, the harvested crop will have a high percentage of damage resulting in low yield and possible rejection of the entire crop. Other catastrophic consequences of a failure to meet the objectives by the drivers may be a damaged or destroyed conveyer. This would in turn necessitate repairs and probably result in a decrease in harvesting time and possibly unharvested crop or destruction of part of the crop. It is of prime importance that the operators of the harvest vehicle and the collection vehicle be able to operate in close cooperation. The degree of cooperation could be greatly increased if each driver had fewer matters with which to concern himself. One of the most crucial factors with which each driver is concerned is the positioning of the conveyer with respect to the container on the collection vehicle and the level of the crop.
It is thus an object of the present invention to provide a control means for automatically and regulating the vertical and horizontal position of the conveyer means with respect to the container on the collection vehicle. It is a further object of the invention to activate an audible alarm warning the drivers in the event that the end of the conveyer means approaches either end of the container. It is a further object of the invention to provide a means to automatically raise the conveyer means above the walls of the container in the event that the drivers fail to correctly respond to the alarm.
It is again an object of this invention to automatically maintain the height of the conveyer means above the level of the crop already deposited in the container. This insures that the crop being deposited in the container does not fall more than a preselected distance thereby reducing the damage resulting from the fall of the crop into the vehicle. It also insures that the conveyer means will not impact this crop. It is a general object of the invention to increase the efficiency of the harvest vehicle and to increase the yield of the harvest.
Other objects and advantages of the present invention will become apparent upon inspection of the accompanying figures and the detailed description of the present embodiment of the invention.